Can Pack of Wonders and cards with 'Spend my Buff' abilities be used at reaction speed, or only at sorcery speed on your turn?

Ruling: Pack of Wonders and 'Spend my Buff' abilities are activated abilities without the Reaction keyword, so they must be used at base speed on your turn, outside of combat, and while there is no open chain.

Sequence:

• Must be on your turn
• Must be outside of combat
• Must be while there is no open chain

Nuances:

• Rules text in Riftbound is literal - if there is no Reaction keyword listed, it cannot be used at reaction speed